CA1159493A - Dual rotating mechanical lock - Google Patents
Dual rotating mechanical lockInfo
- Publication number
- CA1159493A CA1159493A CA000379636A CA379636A CA1159493A CA 1159493 A CA1159493 A CA 1159493A CA 000379636 A CA000379636 A CA 000379636A CA 379636 A CA379636 A CA 379636A CA 1159493 A CA1159493 A CA 1159493A
- Authority
- CA
- Canada
- Prior art keywords
- rod
- coil spring
- spring
- axis
- actuating lever
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- 230000009977 dual effect Effects 0.000 title abstract description 3
- 230000033001 locomotion Effects 0.000 claims abstract description 22
- 230000001154 acute effect Effects 0.000 claims description 3
- 230000008520 organization Effects 0.000 description 1
- 230000002040 relaxant effect Effects 0.000 description 1
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16B—DEVICES FOR FASTENING OR SECURING CONSTRUCTIONAL ELEMENTS OR MACHINE PARTS TOGETHER, e.g. NAILS, BOLTS, CIRCLIPS, CLAMPS, CLIPS OR WEDGES; JOINTS OR JOINTING
- F16B7/00—Connections of rods or tubes, e.g. of non-circular section, mutually, including resilient connections
- F16B7/04—Clamping or clipping connections
- F16B7/0406—Clamping or clipping connections for rods or tubes being coaxial
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16B—DEVICES FOR FASTENING OR SECURING CONSTRUCTIONAL ELEMENTS OR MACHINE PARTS TOGETHER, e.g. NAILS, BOLTS, CIRCLIPS, CLAMPS, CLIPS OR WEDGES; JOINTS OR JOINTING
- F16B7/00—Connections of rods or tubes, e.g. of non-circular section, mutually, including resilient connections
- F16B7/10—Telescoping systems
- F16B7/14—Telescoping systems locking in intermediate non-discrete positions
- F16B7/1481—Telescoping systems locking in intermediate non-discrete positions with a gripping helical spring
Landscapes
- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Mechanical Control Devices (AREA)
- Lock And Its Accessories (AREA)
Abstract
DUAL ROTATING MECHANICAL LOCK
Abstract of the Disclosure A mechanical lock of the type in which axial translational movement of a rod is prevented by a coil spring which encircles the rod and grips it and being readily released by application of a relatively small force through a relatively short stroke, thereby permitting the mechanical lock to be controlled by a pushbutton con-trol. Rotating bushings adjacent the ends of the springs have beveled faces which cause the locking turns at the ends of the spring to become cocked on the rod to provide a true locking action. The device is unlocked by rotation of the rotating bushings, which unwind the locking turns of the spring, thereby releasing the grip of the spring on the rod.
The rotating bushings are rotated in opposite directions by actuating levers which extend outside of the housing of the device. The actuating levers are provided with rollers and are located at the same station along the axis of the rod. A symmetrical wedge-shaped cam is mounted so that it can be drawn axially between the rollers, forcing them apart circumferentially and thereby rotating the actuating lever about the axis of the rod. The wedge-shaped cam is drawn in an axial direcion by a cable which is connected to the pushbutton control. The structure of the device simplifies its assembly, thereby reducing the production cost.
Abstract of the Disclosure A mechanical lock of the type in which axial translational movement of a rod is prevented by a coil spring which encircles the rod and grips it and being readily released by application of a relatively small force through a relatively short stroke, thereby permitting the mechanical lock to be controlled by a pushbutton con-trol. Rotating bushings adjacent the ends of the springs have beveled faces which cause the locking turns at the ends of the spring to become cocked on the rod to provide a true locking action. The device is unlocked by rotation of the rotating bushings, which unwind the locking turns of the spring, thereby releasing the grip of the spring on the rod.
The rotating bushings are rotated in opposite directions by actuating levers which extend outside of the housing of the device. The actuating levers are provided with rollers and are located at the same station along the axis of the rod. A symmetrical wedge-shaped cam is mounted so that it can be drawn axially between the rollers, forcing them apart circumferentially and thereby rotating the actuating lever about the axis of the rod. The wedge-shaped cam is drawn in an axial direcion by a cable which is connected to the pushbutton control. The structure of the device simplifies its assembly, thereby reducing the production cost.
Description
r-6~60 7 The present invention is in the field of mechanical 8 locking devices and specifically relates to a device of the 9 type in which the locking is effected by a coiled spring which grips a rod, for clamping two members against translational 11 motion and for selectively enabling such motion when the ends 12 of the springs are twisted in opposite directions simultaneously 13 to unwind the coiled springs, thereby relaxing its grip on the 14 rod.
17 The present invention includes a rod which extends ~
18 into a cyiindrical housina. Normally, the present invention 19 locks the rod with respect to the housing so that axial trans-lational motion of the rod relative to the housing is prevented.
21 The mechanical lock can be selectively actuated to an unlocked 22 state in which motion of the rod is enabled. In the present 23 invention, the opposite ends of the spring are each connected 24 to actuator levers which are used to rotate the opposite ends
17 The present invention includes a rod which extends ~
18 into a cyiindrical housina. Normally, the present invention 19 locks the rod with respect to the housing so that axial trans-lational motion of the rod relative to the housing is prevented.
21 The mechanical lock can be selectively actuated to an unlocked 22 state in which motion of the rod is enabled. In the present 23 invention, the opposite ends of the spring are each connected 24 to actuator levers which are used to rotate the opposite ends
2~ of the spring in opposite directions to unwind the spring, so 26 that its diameter increases slightly, thereby causing the spring 27 to relax its grip on the rod, which may then be moved freely 28 axially relative to the housing.
D-,8~0 ~.~5,9~3 1 The use of a coiled spring to grip a rod exten-2 ding coaxially throuyh the spring is well known. A number
D-,8~0 ~.~5,9~3 1 The use of a coiled spring to grip a rod exten-2 ding coaxially throuyh the spring is well known. A number
3 of locking devices making use of this basic principle have
4 been patented. 1~1hile all of the patented devices use this same fundamental principle, the implementations employed 6 are patentably distinct. The present invention is believed 7 to provide still another new and useful implementation.
8 In ~.S. Patent No. 3,230,595 issued January 25, 9 1966 to Kedam, there is shown a rod-clamping device in which both ends of the spring are rotated simultaneously to lock 11 and unlock the device. ~owever, rotation of the ends of the 12 spring is not produced by an actuator lever, but instead by 13 grooves which exert a camming action on the ends of the 14 spring. The device described in Kedam's patent includes no provision for causing the last few turns at each end of the 16 spring to become cocked on the rod to produce a more positive 17 locking engagement.
18 This latter feature is shown clearly in U.S. Patent 19 No. 3,249,180 issued May 3, 1966 to Torossian and in U.S.
Patent No. 2,750,994 issued June 19, 1956 to Howell. However, 21 in these patents, only one end of the spring is rotated to 22 lock and unlock the device and therefore the stroke reauired 23 is longer than in the present invention.
24 In U.S. Patent No. 3,874,480 issued April 1, 1975 to Porter et al., there is described a friction brake mechanism 26 in which two springs are unwound simultaneously to unlock the 27 grip of ~he springs on a rod. Also, in U.S. Patent No. 3,064, 28 766 issued November 20, 1962, Hanizeski shows a spring lock ///
~2 r,~ 60 1 in which two separate springs are simultaneously unwound by 2 an electromagnetic device to produce the desired unlocking.
3 All of the above-mentioned inventions can be dis-4 tinguished on the basis of their structures from the device of the present invention. The present invention arose from 6 the desirability of having a true lockina action of the type 7 wherein the last few turns at the ends of the spring become 8 cocked on the rod, but at the same time being releasable by 9 actuation through a relatively short stroke and by means of a cable which extends in the axial direction; This particular 11 combination of features was unavailable in the known prior art 12 and necessitated the present invention.
l*
19 In the present invention, both ends of the spring are rotated simultaneQusly to unlock the device. This is 2~ done in a balanced manner by means of a novel actuator in 22 which the motion of a cable in a direction parallel to the 23 axis of the rod pulls a wedge-shaped cam between two actuating 24 levers to rotate them equally, but in opposite directions in a balanced manner.
26 The actuating motion is transmitted from the actua-27 ting levers to rotating bushings which in turn engage the ends 28 of the spring. The faces of these rotating bushings adjacent ///
3~ ///
1159A~3 the spring are bevelled so that any force applied to the rod will tend -to cause the last few turns on the spring to become cocked on the rod to provide a true locking engage-ment in which the locking force increases as the disturbing force applied to the rod increases.
Because the spring is unwound from its ends which lockingly engage the rod, a very short stroke of the actua-tor is possible, because it is not necessary for the entire spring to be unwound, but only the first few turns at each end.
The short stroke achieved with the actuator used in the present invention permits pushbuttQn control of the device, which is desirable from a styling and convenience standpoint.
More specifically the invention is a mechanical lock for normally preventing axial motion of a rod with respect to a housing and for selectively permitting such motion when unlocked by an operator, said mechanical lock comprising in combination: a coil spring having a first end and a second end; a rod extending coaxially through said coil spring, the diameter of said rod being slightly larger than the inside diameter of said coil spring when it is not mounted on said rod, so that said coil spring normally grips said rod tightly when mounted on said rod; a first rotatable bushing mounted coaxially on said rod adjacent the first end of said coil spring and including a surface inclined at an acute angle with respect to the axis of said coil spring and so located as to contact a portion of the last coil at the first end of said coil spring, whereby an axial load on said rod in a first direc-tion will cause said last coil to become cocked so as togrip said rod more tightly; a second rotatable bushing mounted coaxially on said rod adjacent the second end of said coil spring and including a surface inclined at an ac~te angle with respect to the axis of said coil spring and so located as to contact a por-tion of the last coil at the second end of said coil spring, whereby an axial load on said rod in a second direction will cause said last coil to become cocked so as to grip said rod more tightly; said first rotatable bushing and said second rotatable bushing engaging said first end and said second end respectively of said coil spring so that when said first rotatable bushing and said second rotatable bushing are rotated about said rod in opposite directions and said coil spring will be slightly unwound at its first end and second end thereby releasing the last coil at the first end of said coil spring and the last coil at the second end of said coil spring from their locking engagement with said rod to permit axial translational motion of said rod with respect to said coil spring.
The novel features which are believed to be characteristic of the invention, both as to organization and method of operation, together with other objects and advantages thereof, will be better understood from the following description considered in connection with the accompanying drawings in which a preferred embodiment of the invention is illustrated by way of example. It is to be expressly understood, however, that the drawings are for the purpose of illustration and description only, and are not intended as a definition of the limits of the invention.
-4a-~5~ ~g~
1 In tl~e drawillgs:
3 Figure 1 is a cross-sectional elevation view of 4 the dual rotating mechanical lock of the present invention in a preferred embodiment;
6 Figure 2 is a cross-sectional view taken in the 7 direction 2--2 indicated in Figure 1 and showing the positions 8 of the actuating levers when the device is in in its normal 9 locked state;
Figure 3 is a top view partially in section of the 11 device of Figure l; and, 12 Figure 4 is a cross-sectional view comparable to 13 Figure 2 and showing the relative position of the actuating 14 levers when.the device has been actuated-to its unlocked state.
16 ~//
17 . ///
~1 -- 5~ --1~9~ 3 3 ~urning now to the drawings, in which like parts 4 are denoted by the same reference nu~eral throughout, it is seen that the preferred embodiment of the invention includes 6 a rod 12 having a mounting 13 at its free end, and selective-7 ly slideable axially within a housing 40 having a mounting 8 attachment 42 at one end. Normally, motion of the rod 12 9 with respect to the housing 40 is prevented by the spring 14 which normally grips the rod 12 tightly.
11 ~otating bushings 20, 22 are located at opposite 12 ends of the spring 14, and axial motion of the rotating bush-13 ings 20, 22 is prevented by the fixed bushing 32, 34, which 14 are swaged to the housing 40.
The spring 14 includes radially-extending tangs 28, 16 30, which fit into axially extending slots 25, 57 in the rota-17 ting bushings 20, 22. The rotating bushings 20, 22 include 18 bevelled faces 24, 26 against which the locking coils 36, 38 19 Of the spring 14 bear, thereby becoming cocked with respect to the rod 12 to lock the rod against axial translational motion 21 with respect ~o the housing 40.
22 Actuating levers 16, 18, best seen in Figures 2 and 23 4, are shaped to encircle the spring 14, and portions 44, 46 of 24 actuating levers extend into the same axially-extending sl~ts 25, 27 in the rotating bushings 20, 22 as the tangs 28, 30 of ~6 the spring 14, so that as the acuating levers are rotated about 27 the axis of the rod, that motion is coupled by the portions 44, 28 46 to the rotating bushings 20, 22 and thence to the tangs 28, ///
-- 6 -- .
~-6~60 115g~3 l 30 of the spring 14 causing the spring to unwind slightly, 2 thereby releasing its grip on the rod 12. Because the loc~ing 3 coils 36,38 of the spring 14 are the coils nearest the end of 4 the springs, and because it is those ends of the spring that are rotated by the rotating bushinas 20, 22, the amount of 6 stroke of the actuating levers 16, 18 is minimized. In some 7 locking devices known in the prior art, it is necessary to 8 unwind the entire length of the spring to release the rod, and 9 this requires a much lonqer stroke than is required in the present invention.
ll Also, in some mechanical locks known in the prior 12 art, two springs are employed, and to unwind both of those 13 springs requires a greater actuating force than is required in 14 the present invention which employs only a single spring.
Because of the reduced stroke and reduced actuating 16 force in the present invention, it is practical to use a push- ;
17 button for unlocking the mechanical lock of the present inven-18 tion. The use of a pushbutton for actuation is very desirable l9 from the standpoint of styling and convenience.
When an operator presses on the control button to 21 release the lock, the cable 48 is drawn to the right as viewed 22 in Figure 1. One of the novel features of the present invention 23 is.the manner in which this motion of the cable is used to 24 operate the actuating levers 16, 18.
As best seen in Fi~ures 3 and 4, each of the actuating ~6 levers 16, 18 includes a roller mounted on it, and in accordance 27 with a preferred embodiment of the invention, rollers 52, 54 28 are forced apart as indicated by the arrows in Figure 3, when ///
D-6860 ~
t 1159i~L'g3 1 the wedge-shaped cam 50 is drawn in the direction shown. This 2 separating movement of the rollers 52, 54 is opposed by the 3 spring 14 which is being unwound as the wedge-shaped cam 50 Ib 4 is drawn between the rollers 52, 54~ This unwinding of the spring 14 releases the yrip of the spring on the rod 12. A
6 plastic housing 56 encloses the roller mechanism and serves to 7 keep foreign matter from contaminating it. In the preferred 8 embodiment, the wedge-shaped cam 50 includes a guide bar 58, 9 which is rigid,as opposed to the flexible cable 48, and grooves 60 in the walls of the plastic housing 56 cooperate with the 11 guide bar 58 to maintain proper alignment of the wedge-shaped 12 cam 50. In an alternative embodiment, a return spring may be 13 included within the plastic housing 56 to urge the wedge-shaped ;~
14 cam 50 leftward as viewed in Figure 3, to its normal locked pOsition.
16 The advantages of using the wedge-shaped cam 50 and 17 the rollers 52, 54 to operate the actuating levers 16, 18 can 18 readily be seen. From Figure 3 it is clear that the actuating 19 levers 16, 18 will be rotated simultaneously in opposite direc-tions about the axis of the rod by equal amounts, thereby in-21 suring that both ends of the spring 14 are unlocked at the 22 same instant. Further, the rollers 52, 54 are centered along a 23 line perpendicular to the axis of the rod 12, and bherefore the 24 forces between the wedge-shaped cam and the rollers 52, 54 are balanced and there is no tendency to produce a torque on the 26 device; the mechanical lock is subjected to an axial force 27 only. Finally, the mechanism employed in the present in~ention 28 is a compact and convenient way of converting an axial motion ///
D-~860 g3 1 of the cable 48 into two balanced opposed rotational motions 2 of the roller.
3 As best seen in Figure 1, assembly of the mechanical 4 lock is simplified by its structure. Typically, the fixed bushing 32, the rotating bushing 20, the spring 14, the ro-6 tating bushing 22, and the fixed bushing 34 are slid onto the 7 rod 12. A slot 60 extends axially in the housing 40 to permit 8 the actuating levers 16, 18 to be slid into position encircling 9 the spring 14. ~ecause this slot would not permit proper swaging at the right-hand end of the device as shown in Figure 1, 11 a sleeve 62 is applied over the housing 40 prior to the swaging 12 operation. Also, a control bracket 64 is positioned adjacent 13 the fixed bushing 34 prior to the swaging operation so that the 14 control bracket 64 will be permanently fastened to the lock when the suaging operation has been completed. The plastic 16 housing 56 consists of two halves in a preferred embodiment, 17 and these snap together and are held at a proper position cir-18 cumferentially by means of a tang in the housing 40.
19 Thus, there has been described a mechanical lock which has a structure that permits the lock to be controlled by a 21 pushbutton. ,This is made possible by the low stroke and actua-22 ting force requirements of the device. It is also seen that the 23 structure of the device facilitates assembly of the mechanical 24 lock and this, in turn, helps to reduce the production costs.
The foregoing detailed description is illustrative of 26 a preferred embodiment of the invention, but it will be under-27 stood that additional embodiments thereof will be obvious to 28 those skilled in the art. The embodiments aescribed herein, to-29 gether with those additional embodiments are considered to be within the scope of the invention.
_ 9 _
8 In ~.S. Patent No. 3,230,595 issued January 25, 9 1966 to Kedam, there is shown a rod-clamping device in which both ends of the spring are rotated simultaneously to lock 11 and unlock the device. ~owever, rotation of the ends of the 12 spring is not produced by an actuator lever, but instead by 13 grooves which exert a camming action on the ends of the 14 spring. The device described in Kedam's patent includes no provision for causing the last few turns at each end of the 16 spring to become cocked on the rod to produce a more positive 17 locking engagement.
18 This latter feature is shown clearly in U.S. Patent 19 No. 3,249,180 issued May 3, 1966 to Torossian and in U.S.
Patent No. 2,750,994 issued June 19, 1956 to Howell. However, 21 in these patents, only one end of the spring is rotated to 22 lock and unlock the device and therefore the stroke reauired 23 is longer than in the present invention.
24 In U.S. Patent No. 3,874,480 issued April 1, 1975 to Porter et al., there is described a friction brake mechanism 26 in which two springs are unwound simultaneously to unlock the 27 grip of ~he springs on a rod. Also, in U.S. Patent No. 3,064, 28 766 issued November 20, 1962, Hanizeski shows a spring lock ///
~2 r,~ 60 1 in which two separate springs are simultaneously unwound by 2 an electromagnetic device to produce the desired unlocking.
3 All of the above-mentioned inventions can be dis-4 tinguished on the basis of their structures from the device of the present invention. The present invention arose from 6 the desirability of having a true lockina action of the type 7 wherein the last few turns at the ends of the spring become 8 cocked on the rod, but at the same time being releasable by 9 actuation through a relatively short stroke and by means of a cable which extends in the axial direction; This particular 11 combination of features was unavailable in the known prior art 12 and necessitated the present invention.
l*
19 In the present invention, both ends of the spring are rotated simultaneQusly to unlock the device. This is 2~ done in a balanced manner by means of a novel actuator in 22 which the motion of a cable in a direction parallel to the 23 axis of the rod pulls a wedge-shaped cam between two actuating 24 levers to rotate them equally, but in opposite directions in a balanced manner.
26 The actuating motion is transmitted from the actua-27 ting levers to rotating bushings which in turn engage the ends 28 of the spring. The faces of these rotating bushings adjacent ///
3~ ///
1159A~3 the spring are bevelled so that any force applied to the rod will tend -to cause the last few turns on the spring to become cocked on the rod to provide a true locking engage-ment in which the locking force increases as the disturbing force applied to the rod increases.
Because the spring is unwound from its ends which lockingly engage the rod, a very short stroke of the actua-tor is possible, because it is not necessary for the entire spring to be unwound, but only the first few turns at each end.
The short stroke achieved with the actuator used in the present invention permits pushbuttQn control of the device, which is desirable from a styling and convenience standpoint.
More specifically the invention is a mechanical lock for normally preventing axial motion of a rod with respect to a housing and for selectively permitting such motion when unlocked by an operator, said mechanical lock comprising in combination: a coil spring having a first end and a second end; a rod extending coaxially through said coil spring, the diameter of said rod being slightly larger than the inside diameter of said coil spring when it is not mounted on said rod, so that said coil spring normally grips said rod tightly when mounted on said rod; a first rotatable bushing mounted coaxially on said rod adjacent the first end of said coil spring and including a surface inclined at an acute angle with respect to the axis of said coil spring and so located as to contact a portion of the last coil at the first end of said coil spring, whereby an axial load on said rod in a first direc-tion will cause said last coil to become cocked so as togrip said rod more tightly; a second rotatable bushing mounted coaxially on said rod adjacent the second end of said coil spring and including a surface inclined at an ac~te angle with respect to the axis of said coil spring and so located as to contact a por-tion of the last coil at the second end of said coil spring, whereby an axial load on said rod in a second direction will cause said last coil to become cocked so as to grip said rod more tightly; said first rotatable bushing and said second rotatable bushing engaging said first end and said second end respectively of said coil spring so that when said first rotatable bushing and said second rotatable bushing are rotated about said rod in opposite directions and said coil spring will be slightly unwound at its first end and second end thereby releasing the last coil at the first end of said coil spring and the last coil at the second end of said coil spring from their locking engagement with said rod to permit axial translational motion of said rod with respect to said coil spring.
The novel features which are believed to be characteristic of the invention, both as to organization and method of operation, together with other objects and advantages thereof, will be better understood from the following description considered in connection with the accompanying drawings in which a preferred embodiment of the invention is illustrated by way of example. It is to be expressly understood, however, that the drawings are for the purpose of illustration and description only, and are not intended as a definition of the limits of the invention.
-4a-~5~ ~g~
1 In tl~e drawillgs:
3 Figure 1 is a cross-sectional elevation view of 4 the dual rotating mechanical lock of the present invention in a preferred embodiment;
6 Figure 2 is a cross-sectional view taken in the 7 direction 2--2 indicated in Figure 1 and showing the positions 8 of the actuating levers when the device is in in its normal 9 locked state;
Figure 3 is a top view partially in section of the 11 device of Figure l; and, 12 Figure 4 is a cross-sectional view comparable to 13 Figure 2 and showing the relative position of the actuating 14 levers when.the device has been actuated-to its unlocked state.
16 ~//
17 . ///
~1 -- 5~ --1~9~ 3 3 ~urning now to the drawings, in which like parts 4 are denoted by the same reference nu~eral throughout, it is seen that the preferred embodiment of the invention includes 6 a rod 12 having a mounting 13 at its free end, and selective-7 ly slideable axially within a housing 40 having a mounting 8 attachment 42 at one end. Normally, motion of the rod 12 9 with respect to the housing 40 is prevented by the spring 14 which normally grips the rod 12 tightly.
11 ~otating bushings 20, 22 are located at opposite 12 ends of the spring 14, and axial motion of the rotating bush-13 ings 20, 22 is prevented by the fixed bushing 32, 34, which 14 are swaged to the housing 40.
The spring 14 includes radially-extending tangs 28, 16 30, which fit into axially extending slots 25, 57 in the rota-17 ting bushings 20, 22. The rotating bushings 20, 22 include 18 bevelled faces 24, 26 against which the locking coils 36, 38 19 Of the spring 14 bear, thereby becoming cocked with respect to the rod 12 to lock the rod against axial translational motion 21 with respect ~o the housing 40.
22 Actuating levers 16, 18, best seen in Figures 2 and 23 4, are shaped to encircle the spring 14, and portions 44, 46 of 24 actuating levers extend into the same axially-extending sl~ts 25, 27 in the rotating bushings 20, 22 as the tangs 28, 30 of ~6 the spring 14, so that as the acuating levers are rotated about 27 the axis of the rod, that motion is coupled by the portions 44, 28 46 to the rotating bushings 20, 22 and thence to the tangs 28, ///
-- 6 -- .
~-6~60 115g~3 l 30 of the spring 14 causing the spring to unwind slightly, 2 thereby releasing its grip on the rod 12. Because the loc~ing 3 coils 36,38 of the spring 14 are the coils nearest the end of 4 the springs, and because it is those ends of the spring that are rotated by the rotating bushinas 20, 22, the amount of 6 stroke of the actuating levers 16, 18 is minimized. In some 7 locking devices known in the prior art, it is necessary to 8 unwind the entire length of the spring to release the rod, and 9 this requires a much lonqer stroke than is required in the present invention.
ll Also, in some mechanical locks known in the prior 12 art, two springs are employed, and to unwind both of those 13 springs requires a greater actuating force than is required in 14 the present invention which employs only a single spring.
Because of the reduced stroke and reduced actuating 16 force in the present invention, it is practical to use a push- ;
17 button for unlocking the mechanical lock of the present inven-18 tion. The use of a pushbutton for actuation is very desirable l9 from the standpoint of styling and convenience.
When an operator presses on the control button to 21 release the lock, the cable 48 is drawn to the right as viewed 22 in Figure 1. One of the novel features of the present invention 23 is.the manner in which this motion of the cable is used to 24 operate the actuating levers 16, 18.
As best seen in Fi~ures 3 and 4, each of the actuating ~6 levers 16, 18 includes a roller mounted on it, and in accordance 27 with a preferred embodiment of the invention, rollers 52, 54 28 are forced apart as indicated by the arrows in Figure 3, when ///
D-6860 ~
t 1159i~L'g3 1 the wedge-shaped cam 50 is drawn in the direction shown. This 2 separating movement of the rollers 52, 54 is opposed by the 3 spring 14 which is being unwound as the wedge-shaped cam 50 Ib 4 is drawn between the rollers 52, 54~ This unwinding of the spring 14 releases the yrip of the spring on the rod 12. A
6 plastic housing 56 encloses the roller mechanism and serves to 7 keep foreign matter from contaminating it. In the preferred 8 embodiment, the wedge-shaped cam 50 includes a guide bar 58, 9 which is rigid,as opposed to the flexible cable 48, and grooves 60 in the walls of the plastic housing 56 cooperate with the 11 guide bar 58 to maintain proper alignment of the wedge-shaped 12 cam 50. In an alternative embodiment, a return spring may be 13 included within the plastic housing 56 to urge the wedge-shaped ;~
14 cam 50 leftward as viewed in Figure 3, to its normal locked pOsition.
16 The advantages of using the wedge-shaped cam 50 and 17 the rollers 52, 54 to operate the actuating levers 16, 18 can 18 readily be seen. From Figure 3 it is clear that the actuating 19 levers 16, 18 will be rotated simultaneously in opposite direc-tions about the axis of the rod by equal amounts, thereby in-21 suring that both ends of the spring 14 are unlocked at the 22 same instant. Further, the rollers 52, 54 are centered along a 23 line perpendicular to the axis of the rod 12, and bherefore the 24 forces between the wedge-shaped cam and the rollers 52, 54 are balanced and there is no tendency to produce a torque on the 26 device; the mechanical lock is subjected to an axial force 27 only. Finally, the mechanism employed in the present in~ention 28 is a compact and convenient way of converting an axial motion ///
D-~860 g3 1 of the cable 48 into two balanced opposed rotational motions 2 of the roller.
3 As best seen in Figure 1, assembly of the mechanical 4 lock is simplified by its structure. Typically, the fixed bushing 32, the rotating bushing 20, the spring 14, the ro-6 tating bushing 22, and the fixed bushing 34 are slid onto the 7 rod 12. A slot 60 extends axially in the housing 40 to permit 8 the actuating levers 16, 18 to be slid into position encircling 9 the spring 14. ~ecause this slot would not permit proper swaging at the right-hand end of the device as shown in Figure 1, 11 a sleeve 62 is applied over the housing 40 prior to the swaging 12 operation. Also, a control bracket 64 is positioned adjacent 13 the fixed bushing 34 prior to the swaging operation so that the 14 control bracket 64 will be permanently fastened to the lock when the suaging operation has been completed. The plastic 16 housing 56 consists of two halves in a preferred embodiment, 17 and these snap together and are held at a proper position cir-18 cumferentially by means of a tang in the housing 40.
19 Thus, there has been described a mechanical lock which has a structure that permits the lock to be controlled by a 21 pushbutton. ,This is made possible by the low stroke and actua-22 ting force requirements of the device. It is also seen that the 23 structure of the device facilitates assembly of the mechanical 24 lock and this, in turn, helps to reduce the production costs.
The foregoing detailed description is illustrative of 26 a preferred embodiment of the invention, but it will be under-27 stood that additional embodiments thereof will be obvious to 28 those skilled in the art. The embodiments aescribed herein, to-29 gether with those additional embodiments are considered to be within the scope of the invention.
_ 9 _
Claims (2)
1. A mechanical lock for normally preventing axial motion of a rod with respect to a housing and for selectively permitting such motion when unlocked by an operator, said mechanical lock comprising in combination:
a coil spring having a first end and a second end;
a rod extending coaxially through said coil spring, the diameter of said rod being slightly larger than the in-side diameter of said coil spring when it is not mounted on said rod, so that said coil spring normally grips said rod tightly when mounted on said rod;
a first rotatable bushing mounted coaxially on said rod adjacent the first end of said coil spring and in-cluding a surface inclined at an acute angle with respect to the axis of said coil spring and so located as to contact a portion of the last coil at the first end of said coil spring, whereby an axial load on said rod in a first direction will cause said last coil to become cocked so as to grip said rod more tightly;
a second rotatable bushing mounted coaxially on said rod adjacent the second end of said coil spring and in-cluding a surface inclined at an acute angle with respect to the axis of said coil spring and so located as to contact a portion of the last coil at the second end of said coil spring, whereby an axial load on said rod in a second direc-tion will cause said last coil to become cocked so as to grip said rod more tightly;
said first rotatable bushing and said second rota-table bushing engaging said first end and said second end respectively of said coil spring so that when said first rotatable bushing and said second rotatable bushing are ro-tated about said rod in opposite directions said coil spring will be slightly unwound at its first end and second end thereby releasing the last coil at the first end of said coil spring and the last coil at the second end of said coil spring from their locking engagement with said rod to permit axial translational motion of said rod with respect to said coil spring.
a coil spring having a first end and a second end;
a rod extending coaxially through said coil spring, the diameter of said rod being slightly larger than the in-side diameter of said coil spring when it is not mounted on said rod, so that said coil spring normally grips said rod tightly when mounted on said rod;
a first rotatable bushing mounted coaxially on said rod adjacent the first end of said coil spring and in-cluding a surface inclined at an acute angle with respect to the axis of said coil spring and so located as to contact a portion of the last coil at the first end of said coil spring, whereby an axial load on said rod in a first direction will cause said last coil to become cocked so as to grip said rod more tightly;
a second rotatable bushing mounted coaxially on said rod adjacent the second end of said coil spring and in-cluding a surface inclined at an acute angle with respect to the axis of said coil spring and so located as to contact a portion of the last coil at the second end of said coil spring, whereby an axial load on said rod in a second direc-tion will cause said last coil to become cocked so as to grip said rod more tightly;
said first rotatable bushing and said second rota-table bushing engaging said first end and said second end respectively of said coil spring so that when said first rotatable bushing and said second rotatable bushing are ro-tated about said rod in opposite directions said coil spring will be slightly unwound at its first end and second end thereby releasing the last coil at the first end of said coil spring and the last coil at the second end of said coil spring from their locking engagement with said rod to permit axial translational motion of said rod with respect to said coil spring.
2. The mechanical lock of Claim 1 further com-prising:
a first actuating lever connected to said first rotatable bushing and rotatable about the axis of said rod;
a second actuating lever connected to said second rotatable bushing and rotatable about the axis of said rod;
said first actuating lever and said second actua-ting lever positioned at the same location along the axis of said rod and spaced circumferentially from each other;
a wedge-shaped cam mounted for motion in a direc-tion parallel to the axis of said rod and positioned cir-cumferentially between said first actuating lever and said second actuating lever to force said first actuating lever and said second actuating lever apart when said wedge-shaped cam is drawn in the direction parallel to the axis of said rod, whereby said first actuating lever and said second actuating lever are rotated about the axis of the rod simultaneously in opposite senses by equal amounts to unlock the first end and the second end of said coil spring.
a first actuating lever connected to said first rotatable bushing and rotatable about the axis of said rod;
a second actuating lever connected to said second rotatable bushing and rotatable about the axis of said rod;
said first actuating lever and said second actua-ting lever positioned at the same location along the axis of said rod and spaced circumferentially from each other;
a wedge-shaped cam mounted for motion in a direc-tion parallel to the axis of said rod and positioned cir-cumferentially between said first actuating lever and said second actuating lever to force said first actuating lever and said second actuating lever apart when said wedge-shaped cam is drawn in the direction parallel to the axis of said rod, whereby said first actuating lever and said second actuating lever are rotated about the axis of the rod simultaneously in opposite senses by equal amounts to unlock the first end and the second end of said coil spring.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US06/160,133 US4425987A (en) | 1980-06-16 | 1980-06-16 | Dual rotating mechanical lock |
| US160,133 | 1988-02-25 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1159493A true CA1159493A (en) | 1983-12-27 |
Family
ID=22575660
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000379636A Expired CA1159493A (en) | 1980-06-16 | 1981-06-12 | Dual rotating mechanical lock |
Country Status (6)
| Country | Link |
|---|---|
| US (1) | US4425987A (en) |
| CA (1) | CA1159493A (en) |
| DE (1) | DE3121768A1 (en) |
| FR (1) | FR2484666A1 (en) |
| GB (1) | GB2077840B (en) |
| IT (1) | IT1138390B (en) |
Families Citing this family (22)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4577730A (en) * | 1983-08-30 | 1986-03-25 | P. L. Porter Company | Mechanical lock |
| US4901829A (en) * | 1988-03-17 | 1990-02-20 | Stone & Webster Engineering Corp. | Frictional shock absorber enclosed within a housing |
| US4880084A (en) * | 1988-07-05 | 1989-11-14 | P. L. Porter Company | Mechanical linear lock with redundant locking feature |
| US5441129A (en) * | 1993-06-08 | 1995-08-15 | P. L. Porter Co. | Precision linear mechanical lock |
| US5568843A (en) * | 1993-06-08 | 1996-10-29 | P. L. Porter Co. | Precision linear mechanical lock |
| US5819881A (en) * | 1995-07-24 | 1998-10-13 | P. L. Porter Co. | Dual locking linear mechanical lock for high loads |
| US5609229A (en) * | 1995-09-05 | 1997-03-11 | Ingersoll-Rand Company | Actuator arrangement for a band brake |
| US5833317A (en) * | 1995-11-27 | 1998-11-10 | Lear Corporation | Automotive seat back recliner |
| US5634534A (en) * | 1996-04-09 | 1997-06-03 | Tachi-S Co., Ltd. | Longitudinal locking mechanism for vehicle seat |
| US5794470A (en) * | 1996-06-25 | 1998-08-18 | P.L. Porter Co. | Mechanical seat lock |
| JP3493000B2 (en) | 1998-02-03 | 2004-02-03 | サンライズ メディカル エイチエイチジー インコーポレイテッド | Wheelchair back recliner kit |
| IT1301738B1 (en) * | 1998-06-17 | 2000-07-07 | Luciano Migliori | SPRING LOCKING DEVICE, FOR MOTION-MOVING CONTROL UNIT. |
| US6520584B1 (en) | 1998-10-13 | 2003-02-18 | Magna Seating Systems Inc. | Adjustment mechanism for an automotive seat |
| WO2000056570A1 (en) | 1999-03-24 | 2000-09-28 | Magna Seating Systems Inc. | A manual adjustment mechanism for a vehicle |
| DE102005003613A1 (en) * | 2005-01-26 | 2006-07-27 | Rexroth Mecman Gmbh | Pressurised medium cylinder has piston rod running through coil spring clamping element to clamp with friction engagement which can be released by elastically deforming spring |
| US7314019B1 (en) | 2006-04-19 | 2008-01-01 | Suzanna Curi | Retractable step with secure locking mechanism |
| US7766311B2 (en) * | 2007-07-30 | 2010-08-03 | Takonix Incorporated | Wireform locking device |
| US10018009B2 (en) * | 2015-02-26 | 2018-07-10 | Cameron International Corporation | Locking apparatus |
| JP6420737B2 (en) * | 2015-09-10 | 2018-11-07 | タカノ株式会社 | Work aid |
| US20190168640A1 (en) | 2016-07-28 | 2019-06-06 | Adient Luxembourg Holding S.À R.L. | Seat system |
| US10933787B2 (en) | 2016-08-19 | 2021-03-02 | Adient Luxembourg Holding S.Á R.L. | Head restraint follower |
| US10759318B2 (en) | 2016-08-19 | 2020-09-01 | Adient Luxembourg Holding S.Á R.L. | Infinite adjustment mechanism for a head restraint |
-
1980
- 1980-06-16 US US06/160,133 patent/US4425987A/en not_active Expired - Lifetime
-
1981
- 1981-06-02 DE DE19813121768 patent/DE3121768A1/en not_active Ceased
- 1981-06-02 GB GB8116881A patent/GB2077840B/en not_active Expired
- 1981-06-12 IT IT22302/81A patent/IT1138390B/en active
- 1981-06-12 CA CA000379636A patent/CA1159493A/en not_active Expired
- 1981-06-15 FR FR8111763A patent/FR2484666A1/en not_active Withdrawn
Also Published As
| Publication number | Publication date |
|---|---|
| GB2077840B (en) | 1984-04-26 |
| FR2484666A1 (en) | 1981-12-18 |
| DE3121768A1 (en) | 1982-03-18 |
| IT8122302A0 (en) | 1981-06-12 |
| IT1138390B (en) | 1986-09-17 |
| GB2077840A (en) | 1981-12-23 |
| US4425987A (en) | 1984-01-17 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |